The graph of the function y = f(x) is symmetrical about the line x = 2, then:

f(x + 2) = f(x - 2) f(2 + x) = f(2 - x) f(x) = f(-x) f(x) = -f(-x)

f(2 + x) = f(2 - x)

If y = f(x) is symmetric about the line x = 2 then f(2 + x) = f(2 - x).